Toggle actuated plier wrench



June 30, 1953 J. JOHNSON TOGGLE ACTUATED PLIER WRENCH 3 Sheets-Sheet 1 Filed Sept. 28, 1951 N3" m i INVENTOR w AoHN JouusoN US 03 w:

r 6N mu 0 mm 0 W M w June 30, 1953 J. JOHNSON 2,643,567

TOGGLE ACTUATED PLIER WRENCH Filed Sept. 28, 1951 3 Sheets-Sheet 2 INVENTOR JoHN JOHNSON June 30, 1953 J, JOHNSON TOGGLE ACTUATED PLIER WRENCH 3 Sheets-Sheet 3 Filed Sept. 28, 1951 ATTORNEYS JOHN Jouusou BY 7Z Wflmm rflmwm w smh mm- 6m Patented June 30, 1953 UNITED STATES PATENT OFFICE TOGGLE ACTUATED PLIER WRENCH John Johnson, Brockton, Mont.

Application September 28, 1951, Serial No. 248,684

11 Claims.

This invention relates to pliers or wrenches. More particularly, the invention has reference to an articulated wrench of the type including a pair of pivoted, toggle-actuated jaws capable of being releasably locked to a piece of work.

Conventionally, in wrenches falling within the category referred to the jaws are so pivoted that the work-engaging faces thereof are related angularly to one another in various positions to which the jaws are swung. In this connection, the angle at which one jaw face is disposed relative to the other will vary according to the distance between the faces. The distance between the faces, obviously, will in turn be varied during the use of the tool, and will be established on each occasion of use by the thickness of the particular work piece engaged by the jaw faces. It follows, therefore, that the thickness of the work will determine the angle of the jaw faces to one another, and it is also a fact that the jaws will operate with less efficiency in gripping the work when disposed at one angle relative to one another than they will when disposed at another angle. For example, the angular relation of the jaw faces will in many instances prevent them from engaging a work piece of circular cross sectional configuration at diametrically opposite locations, as a result of which a tendency toward slippage asserts itself.

The present invention has as one important purpose the provision of a plier-wrench which will have pivotally mounted, toggle lever-actuated jaws, thus embodying in the construction the powerful leverage inherent in wrenches of this type, but which will at the same time be so designed as to cause the jaw faces to be disposed in parallel planes in all positions to which the jaws are adjusted relative to one another, thus to eliminate the deficiency noted above as being present in conventional construction.

Additionally, it may be noted that in conventionally constructed wrenches or pliers of the type referred to, locking of the jaws to the work occurs when the toggle commonly embodied in such wrenches passes across a dead center. This is desirable when the wrench is used as a clamp or vise. However, this characteristic is annoying and time-consuming when the tool is used as a ratchet or pipe wrench.

Such a tool is capable of being adjusted, most usually, so that it will not look, but when so adjusted the greatest advantage thereof is lost, namely, the tremendous leverage exerted by the toggle lever arrangement. Since the pressure required to bring the toggle back across a dead center and thus unlock it is equal to that exerted during the locking of the toggle, and further since the unlocking pressure must be applied in a reverse direction, it is usually awkward and difficult to perform this operation with the back of the fingers of the hand in which the wrench is held. As a result, it is often found necessary to unlock the wrench with the other hand. In many instances, this represents a decided inconvenience.

Accordingly, it is another important object of the present invention to provide a wrench falling within the general category stated, which will have an improved locking mechanism that will be operative only when desired by the user. Thus, when the tool formed in accordance with the present invention is used as a ratchet or pipe wrench, the'jaws may be released instantly when pressure on the handles is relaxed even though the tool may be adjusted for maximum gripping power. It is proposed to attain this result through a construction wherein the toggle joint will move close to a dead center so as to obtain a maximum amount of gripping power. However, the movement past a dead center will be prevented by a stop means embodied in the locking mechanism so that automatic locking of the jaws is ordinarily prevented. When, however, it is desired to lock the jaws to the work, a trigger is readily operable by the user to set into operation the locking mechanism which I have devised. Subsequently, simple pressure by the user tending to urge the handles of the tool toward one another is effective to automatically disengage said mechanism. In this way, the tool is readily usable not only as a clamp or vise, but also, as a ratchet or pipe wrench, at the option of the user.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a top plan view in which a portion of one handle has been broken away;

'Figure 2 is a longitudinal sectional view taken substantially on line 2-2 of Figure 1;

Figure 3 is a longitudinal sectional view taken substantially on line 3-3 of Figure 2;

Figure 4 is a longitudinal sectional view taken substantially on line 4-4 of Figure 3;

Figure 5 is an enlarged front elevational View;

Figure 6 is an enlarged transverse sectional view taken substantially on line 6-6 of Figure 2;

Figure '7 is an enlarged transverse sectional view through a portion of the locking mechanism, taken substantially on line l--'| of Figure 2;

Figure 8 is an enlarged longitudinal sectional view through said portion of the locking mechanism, taken substantially on line 8-8 of Figure 3.

Figure 9 is a side elevational view in which one of the cover plates has been removed, one of the handles being shown partially in longitudinal section; and

Figure 10 is a view similar to Figure 4: and illustrating a modified form.

Referring to the drawings in detail, a handlemember l2 has a channeled innerend portion and a tubular outer end portion. Formed in-the bight of the inner end portion is a pairof parallel, longitudinal slots l4. These receive the reduced ends l6 of a pair of parallel cover platesi8, said plates being of flat formation and extendin from the handle member I2 in parallelism along opposite sides of the tool, substantially to the head end of the tool. For the greatest part of their length, the cover plates l8 are of substantially widened dimensions, so as to enclose protectively and afford a support for the articulated linkage embodied in the device.

The cover plates l8 are fixedly secured to the handle member I2 in any suitable manner, as by rivets, welding, or integral formation with the handle member.

Fixedly mounted in the tubular outer end portion of the handle member 12 is a bushing 20, having an end to end threaded bore in which is threadedly engaged a tubular adjusting screw 22, having right-hand external threads. The adjusting screw projects rearwardly from. the handle member l2, and. the projecting portion of the screw is integral with or otherwise fixedly connected to a turning knob 24.

The adjusting screw 22 is formed with internal threads engaged by left-hand. threads provided upon a toggle holder 25 the free end of which is bifurcated as at 26.

The purpose of this arrangement is to effect faster adjustments and shorter travel of. the adjusting screw, and also to provide means adapted to prevent the toggle holder from slipping, out of place.

Pivotally connected to the bifurcated end of the screw is one end of an actuating lever 28; which extends obliquely from the handle comprising the handle member l2 and the cover plates I 8, and at its other end; has a pivotal connection 30 to a second handle 32.

For clarity in description, the handle first described will be hereinafter referred to asa fixed handle, while the handle 32 will be referred to as a movable handle.

I believe it will be apparent, from the description so far provided, that when thefixed andmovable handles are grasped by the hand of a user, pressure exerted by the user tending to press the handles together will be operative to impart movement to the handle 32 longitudinally of the fixed handle in the direction of the head or work-engaging end of the tool. This is so because such pressure will cause movement of the pivotal connection 30 in an arcuate path about the pivotal connection at the other end of the actuating lever 28, toward the left in Figures 2' and 9. Such movement will naturally tend to carry with it the movable handle 32.

The movable handle 32 is integrally formed with a widened inner end portion 34 arranged longitudinally and centrally of the tool as best shown in Figure 6. The outer end portion of 4 the movable handle, it may be noted, is of charineled formation, to enclose the locking mecha-.- nism embodied in the invention, and to be described hereinafter.

A pivot pin 36 serves to articulate the inner end portion 34 of the movable handle to one end of a pair of identically formed, parallel lever members 38 of longitudinally curved formation, that embrace the inner end portion 34 of the movable handle at said end thereof;

The lever members 38 together may be termed a main lever and will be so designated hereinafter.

The main" lever is fulcrumed medially between opposite ends thereof upon a main pivot pin 40 which, as may be noted from Figure 2, is of square cross-section. The pin, as will also be noted from Figure 3, has reduced ends riveted to the respective cover plates Hi.

It will be appreciated" that on shifting of the movable handle 32' to the left in the several figures of the drawing, the main lever will be caused to rock on the main pivot pin 40, so that the end ofthe main lever remote from the movable handle will begiven movement in a reverse di-- rection; away from the work-engaging'end of the tool.

In Figure 10', there is illustrated a modified form of main pivot, comprising a-rivet 42 extending between the cover plates I8 on which is provided a roller 43 on whichthemain lever is rockably mounted.

Pivotallyconnected to that endof the main lever that moves away-from the head of the tool when the handles are pressed together; through the medium of a pivot pin 44, is a connecting link 46., The connecting link 46-;isof arcuate formation, and is connected to the main lever at one end,'said end extendingbetweenthe lever members 38.

The other end of the connecting link' 46 is blfurcated, and hasa pivotalconnection to a center plate generally designated 58. The center plate 50 "is parti'cul'arlywell sh0.wn-in Figure 4, wherein'it is' seen that the plate is straddledby the bifurcated end of the link 46,; contiguous to-the head end of said plate;

Itwill thusbe seen that when the main lever is rocked in the manner described above, the link 46 will be shifted in a direction away from the head end of the tool, and willbe effective to shift the center plate 50in the same'direction.

The center plate '50-is disposed medially'between and inparallel relation to the cover plates l8, and at its foot end, is provided withan elongated; longitudinal, closed slot-52 through which extends a flattened guide lug 54; The guide lug 54 extends transversely between the cover plates l8; and is rigidly secured at'opposite ends, to the inner faces of said plates.

In Figure 10, the center plate has a slot 58 slightly wider than the slot 52"corresponding thereto in the first form of the invention, a pin 60 extending transversely between the cover plates i8 and being rigidly secured to said. cover plates. The pin 60 extends, through the slot 58', and is provided with a roller 62;

Inboth forms of the invention, the center plate, when shifted longitudinally of the tool, has straight line movement, said'straight line movement being provided for not only by the provision of the longitudinal slots and guide means extending therethrough, butalso through the provision of-a second longitudinal slot 64 through which the main pivot extends, the main pivotthus serving as a second guide means cooperating with the guide means 54 or, 62. Slots 52, 64 are in exact parallelism.

Movement of the center plate away from the head end of the tool is against the action of a spring 6%, one end of which is engaged with said plate, and the other end of which is engaged by a transverse abutment 68 secured by rivets III to the side walls of the channeled handle member i2. Thus, whenever pressure on the fixed and movable handles tending to urge them toward one another is released (and. assuming that the locking mechanism is arranged inoperatively) the spring 66, tending to expand, will bias the.

center plate toward the head of the tool and will therefore tend to normally spread the handles.

At the head end of the center plate 50, transversely spaced pivot pins I2 are provided upon the center plate, said pivot pins serving to articulate to the plate a pair of front toggle links 14.

At their other ends, the toggle links I4 are pivotally connected at 16 to a pair of work-engaging jaws l1, I8 which for purposes of clarity will be referred to as an upper jaw and a lower jaw.

The lower jaw includes a pair of elongated, parallel jaw plates 'I'I that extend longitudinally of the tool between the cover plates I8, along the lower longitudinal edges of said cover plates. The lower front toggle link extends between and is pivotally connected at It to the jaw plates I7, while the upper front toggle link extends between and is pivotally connected to a pair of parallel upper jaw plates I3, that are disposed between and in parallelism with the cover plates is adjacent the upper longitudinal edges of said cover plate.

Rigidly connecting the lower jaw plates 11 at the head end of the tool is a serrated, work-gripping jaw face E9. An upper jaw face 30 cooperates with the lower jaw face I9 in gripping a piece of work, not shown, and similarly connects the upper jaw plates 18. Movement of the center plate 59 away from the head end of the tool is effective to impart movement in the same di rection to the pivotal connections I2, as a result of which the toggle links I4 will be swung about said pivotal connections, thus to cause movement of the pivotal connections I6 toward one another. This may be readily noted by comparison of Figures 9 and 4. In Figure 9, the jaws are shown in open position, while in Figure 4, the jaws are shown in a closed position. In each of these positions, the jaw faces 19, 80 are in parallel relation.

Disposed between the respective jaws and the cover plates are upper and,lower front control links 82. These are pivotally connected at one end to the jaw plates associated therewith through the medium of the pivotal connections I6, and are pivotally connected at their other ends, as at 84, to the cover plates.

, Upper rear control links 86 are also disposed between the jaw plates and the cover plates, at the inner end of said jaw plates. These are pivotally connected at one end to the cover plates by pivot pins 88.

The links 85 are associated with the upper jaw plates, and for association with the lower jaw plates, I provide lower rear control links 90 which are pivotally connected at 92 to the cover plates.

.Pivotal connections 94 serve to articulate the upper rear control links 86 to the inner ends of the upper jaw plates I8, while corresponding pivotal connections 96 are employed to provide an articulated connection between the lower rear control links and the lower jaw plates 11.

Rear toggle links areprovided, that connect the inner ends of the jaw plates to the center plate 50, so as to cooperate with the front toggle links I4 in shifting the jaw faces toward and away from one another. To this end, upper links 98 are disposedat opposite sides of, and pivotally connected at I00 to the center plate, said links 98 being articulated to the upper jaw plates "I8 through the medium of pivotal connections 94. Lower rear toggle links I02 are pivotally joined at I04 to the center plate, and at 96 to the lower jaw plates 'I'I.

Through the provision of the front and rear control links, both jaws are articulated to the fixed handle I2, at locations spaced longitudinally of said handle and jaws. Thus, the pivotal connections I6 of the front control links and the pivotal connections 94, 96 of the rear control links swing about the pivotal connections 84 of thefront control links and the pivotal connections 88, 92 of the rear control links when the center plate is shifted away from the head end of the tool, thus to control the movement of the jaws toward and away from one another when said movement is imparted to the jaws by means of the front and rear toggle links 82 and 98, I02 respectively.

It is to be noted that the jaws faces IQ, 8B are in exact parallelism with the slots 52, 64. In this connection, it should be understood that although the wrench may be constructed with straight jaws or with jaws offset at angles other than that illustrated, it is essential that said jaw faces and slots all be parallel in any position of the jaws, from a fully closed to a fully open position.

Further, the arrangement which I have devised is such (see Figures 2, 4, 9, and 10) that straight lines drawn between the centers of front pivots 84, 84; rear pivots 88, 92; pivot points I2, I2; and pivot points I00, I04, will each be perpendicular to a straight line drawn parallel to the jaw faces.

Referring now to the locking mechanism embodied in the invention, I provide, at the free end of the movable handle 32, a pivot pin I06 (Figures '7 and 8) whereby there is pivotally mounted upon the movable handle a trigger IE8. A spring IIII is'coiled about the pivot pin I06, and normally biases the trigger to an inoperative position illustrated in Figure 9.

. Limiting movement of the trigger Iiiil to said inoperative position thereof are stop lugs II2 integrally formed upon the opposite side walls of the movable handle 32, said stop lugs engaging the inner end of the trigger I08.

The trigger I08 is of channeled formation, and extending inwardly from the opposite side walls thereof are pintles II4 on which a block H6 is rookably mounted. The block H6 is provided with a bore receiving a rod H8 slidable in the block in the direction of its own length.

A coiled spring I20 surrounds the rod I Ill, said spring abutting at one end against the block IIB. For the purpose of limiting movement of the rod I I8 in one direction, I provide a pair of nuts I22, that are threaded upon the rod at one end thereof.

At its other end, the rod I20 is formed with a flattened head I24 guided during sliding movement of the rod II8 by a cross piece I26, that extends between the side walls of the movable member and is rigidly secured to said movable handle, and by guide lugs I28, that overlie the head I24 andare also rigidlyseeured-tothe-moirable handle.

At its free end, the head I24-is ofbeveled formation, and is provided withatrans-verse notch on its under side, receiving a latch hook I30" formed upon the actuating lever 28"intermediate opposite ends of said lever.

The notch formed-upon the head I24' has been designated I32, and is so proportionedas to re'- ceive an upturned lip on the hook I30 whenth'e lever 28- and head I24 are positioned as in'Fig ure 2.

A bumper spring I34- is secured within the.

movable handle 32, and extends longitudinally thereof, said spring being so arranged as to exert upward pressure against the actuatinglever 28' when the fixed and movable handles of the tool are pressed together.

In use, the fixed and movable handles are grasped in the hand of a user, andare-pr'essed toward one another, so as to engage the jaws with apiece of work. In this connection, theknob 24 is rotated as necessary, so as toadjust the jaws preliminary to application thereof to the work, thejaws being preliminarily adjusted to such anextent as will'causethem toengage the work with the-fixed and movable handles spaced apart to the extent illustrated in Figure 2, that is, to an extent as will cause the hook I30 to'be engaged by thebumper spring- I34.

The spring will previously haveurged the trigger I08 to a position in which-the head I24 will be disposed fully to the right ofthehook I30 when viewed as in Figure 2, whenthefixed and movable handles are pressed together. As'

a result, merepressure exerted against the handles tending to move them toward one another will cause the jaws to engage the work securely, but will not set the jawlocking mechanism into operation. However, if the user desires to lockthe jaws to the work, it is merely necessary that This causes the rod IIS to beshiftedbodily' to' the left in Figure 2, to engage the hook l30'and' notch I32, and thus lock the jaws to the work.

At such time as it may be desired to release thejaws, the user merely presses the fixed and movable handles toward one another, against the action of the bumper spring I3"4-,-so that the hook I30 is lowered outof' engagement with the notch I32. The spring I20, tending toexpand, biases the block II6 to the right in Figure-'2," the block carrying with it the rod- I I8 and -thehead I24 so as to disengage the head fullyfrom the hook.

For the purpose of imparting rigidity to: the construction of the tool, and to insure -the proper spacing of the cover plates I8, a; spacer sleeve-I36 may be extended betweentheplates "in advance of the handle member I2, said spacer sleeve being mounted upona rivet I38 rigidly connect;- ing the cover plates.

It is believed clear that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which itm-ay be suited. Nor is the invention to'be necessarily limited tothe specific construction illustrated and described; since suchconstruction is only intended tobeillustrative of the principles of operation and the means presently devised to carry out said min cipl'esg. itbeing considered that the invention comprehends any minor changes in. construction that may be permitted within the scope of the'appended claims.v

It isalso believed-clear that the locking mechanism illustrated and described herein, though illustrated inassociation with a novel jaw actuating assembly, can be readily applied to any conventional lever-jaw wrench, and will function with full efliciency-in wrenches of various types and dimensions;

What is claimed is:

1. A plier-wrench including a fixedhandle; a-

movable handleconnected thereto for swinging movement through a path extending longitudinally'of thefixed handle, the connection of the handlesto one another comprising-an actuating lever pivotally' attached at its ends to therespective handles; a pair of jaws'provi'ded with parallel, work-engaging facesand articulated-to the fixed handle for movement into engagement with a work piece, said jaws being respectively extended longitudinally of thefixed handle, the articulated connection of each jaw to the fixed handle comprising a pair of control links of equal length respectively, connected pivotally at their opposite ends to and spaced longitudinally of the jaw and fixed handle, said links being arranged for swinging movement of the jaws toward and away from one another while holding the jaw faces parallel; a center plate-mounted on the fixed handle to shift longitudinally thereof in a straight line; a linka'ge'between the center plate and the movable handle operative to shift the center plate responsive to movement of the movable. handletoward the fixed handle; and toggle means articulated to the center plate and jaws and effective .to engage the jaws with the work piece responsive to longitudinal shifting oftheoenter plate.

2. ApIier-wrench including, a fixed handle; a movable handle, said movable handle being connected to the fixedhandle. for swinging movement through a path extending longitudinally of the-fixed handle; a pair of jaws provided with parallel, work-engagingfaces and articulated to the fixed handle for movement into engagement with. a. workpiece, saidjaws being respectively extending longitudinally of thefixed-handle, the articulated, connection of each jaw to the fixed handle comprisinga pair of control links of equal length respectively connected'pivotally at their opposite ends to and spaced longitudinally of the jaw and fixed handle,asaid.links being arranged for.swinginggmovement ofithe jaws toward and away. from, one another. while. holding the jaw faces'parallel; acenter plate mounted on the fixed handle for straight-line movement longitudinally thereof; an actuating lever constituting means connecting the movable handle to the fixed handle for swingingmovement, said actuating lever 'beingpivotally connected at opposite ends to the respective handles and being arranged to swing the movable handle longitudinally of the. fixedhandle toward the jaws, on exertion of pressure tending to urge the handles toward one another; direction-reversing, means connecting the movable handle and the center plate for straight-line movement of the center plate longitudinally orthe fixed handleina direction opposite that-given the movable handle; and toggle links'articulated-to the center plate and jaws-andefiective-toengage the jaws with the 9 work piece responsive to said movement of the center plate.

3. A plier-wrench comprising a fixed handle; guide means carried thereby; a movable handle, said movable handle being connected to the fixed handle for swinging movement through a path extending longitudinally of the fixed handle; a pair of jaws provided with parallel, work-engaging faces and articulated to the fixed handle for movement into engagement with a work piece, said jaws being respectively extended longitudinally of the fixed handle, the articulated connection of each jaw to the fixed handle comprising a pair of control links of equal length respectively connected pivotally at their opposite ends to and spaced longitudinally of the jaw and fixed handle, said links being arranged for swinging movement of the jaws toward and away from one another while holding the jaw faces parallel; a center plate slotted longitudinally to receive said guide means, for straight-line movement or the center plate longitudinally of the fixed handle; an actuating lever constituting means connecting the movable handle to the fixed handle for swinging movement, said actuatin lever being pivotally connected at opposite ends to the respective handles and being arranged to swing the movable handle longitudinally of the fixed handle toward the jaws on exertion of pressure tending to urge the handles toward one another; direction-reversing means connecting the movable handle and center plate for straightline movement of the center plate longitudinally of the fixed handle in a direction opposite that given the movable handle; and toggle links articulated to the center plate and jaws respectively and eifective to engage the jaws with the work piece responsive to said movement of the center plate.

4. A plier-wrench comprising a fixed handle; a pivot pin and a guide lug carried by and spaced longitudinally of the fixed handle; a movable handle, said movable handle being connected to the fixed handle for swinging movement through a path extending longitudinally of the fixed handle; a pair of jaws provided with parallel, work-engaging faces and articulated to the fixed handle for movement into engagement with a work piece, said jaws being respectively extended longitudinally of the fixed handle, the articulated connection of each jaw to the fixed handle comprising a pair of control links of equal length respectively connected pivotally at their opposite ends to and spaced longitudinally of the jaw and fixed handle, said links being arranged for swinging movement of the jaws toward and away from one another while holding the jaw faces parallel; a center plate having a pair of spaced longitudinal slots receiving the pin and lug respectively, for straight-line movement of the center plate longitudinally of the fixed handle; an actuating lever constituting means connecting the movable handle to the fixed handle for swinging movement, said actuating lever being pivotally connected at opposite ends to the respective handles and being arranged to swing the movable handle longitudinally of the fixed handle toward the jaws on exertion of pressure tending to urge the handles toward one another; direction-reversing means including a main lever rockable on the pivot pin and having pivotal connections at opposite ends thereof to the movable handle and center plate respectively, for imparting straight-line movement to the center plate longitudinally of the fixed handle in a direction opposite that given the movable handle; and toggle links articulated to the center plate and jaws respectively and effective to engage the jaws with the work piece responsive to said movement of the center plate.

5. A plier-wrench comprising a fixed handle; a pivot pin and a guide lug carried by and spaced longitudinally of the fixed handle; movable handle, said movable handle being connected to the fixed handle for swinging movement through a-path extending longitudinally of the fixed handle; a pair of jaws having parallel work-engaging jaw faces, said jaws being extended longitudinally of the fixed handle and having articulated connections to the fixed handle for movement of the jaws toward one another into engagement with a work piece, the connections of the jaws to the fixed handle being adapted to preserve the parallel relationship of the jaw faces in selected positions to which the jaws are adjusted toward one another, said jaws being respectively extended longitudinally of the fixed handle, the articulated connection of each jaw to the fixed handle comprising a pair of control links of equal length respectively connected pivotally at their opposite ends to and spaced longitudinally of the jaw and fixed handle, said links being arranged for swinging movement of the jaws toward and away from one another while holding the jaw faces parallel; a center plate having a pair of spaced longitudinal slots receiving the pin and lug respectively, for straight-line movement of the center plate longitudinally of the fixed handle; an actuating lever constituting means connecting the movable handle to the fixed handle for swinging movement, said actuating lever being pivotally connected at opposite ends to the respective handles and being arranged to swing the movable handle longitudinally of the fixed handle toward the jaws on exertion of pressure tending to urge the handles toward one another; direction-reversing means including a main lever rockable on the pivot pin and having pivoted connections at opposite ends thereof to the movable handle and center plate respectively, for imparting straight-line movement to the center plate longitudinally of the fixed handle in a direction opposite that given the movable handle; and toggle links articulated to the center plate and jaws respectively and efiective to engage the jaws with the work piece responsive to said movement of the movable handle toward the jaws and said movement of the center plate in an opposite direction.

6. A plier-wrench comprising a fixed handle; a pivot pin and a guide lug carried by and spaced longitudinally of the fixed handle; a movable handle, said movable handle being connected to the fixed handle for swinging movement-through a path extending longitudinally of the fixed handle; a pair of elongated jaws extending longitudinally of the fixed handle and having parallel, work-engaging jaw faces at one end thereof; a plurality of control links spaced longitudinally of the handles and of the respective jaws, said links being pivotally connected at one end to the fixed handle and at their other ends to said jaws to swing the jaws toward one another while preserving the parallel relationship of the jaw faces in selected positions to which the jaws are swung; a center plate arranged within the fixed handle between the jaws and having a pair of spaced longitudinal slots receiving the pin and lug respectively, for straight-line movement of plate longitudinally of the "fixed handle in a direction opposite that given the movable handle; and toggle links articulated to the center 'plate and jaws respectively and effective to engage the jaws with a piece of work' responsive to said movement of the movable handle toward the jaws and said movement of the center plate inan opposite direction.

'7. A plier-wrench comprising a'fixed handle including a pair of rigidly connected, spaced cover plates; a pivot pin and a guidelug secured to and extending transversely between'the cover plates and spaced longitudinally of said'handle; a'movable handle disposed longitudinally of the fixed handle, said movable handle being connected to the fixed handle for swinging movement through a path extending longitudinally of the fixed handle; a pair of elongated jaws extending longitudinally of the fixed handleand having inner end portions extending between the cover plates,

said jaws having parallel, work-engaging jaw faces at their outer ends; control links spaced longitudinally of the cover plates and of the respective jaws, said links being-pivotally connected at one end to the cover plates and atltheir other ends to said jaws to swing the jaws toward one another while preserving the parallel relationship of the jaw faces in selected positions to which the jaws are swung; a center "plate enclosed by the cover plates and disposed between the jaws,

the center plate having a pair of spaced longitudinal slots receiving thepin and lug-respectively, for straight-line'movement of the center plate longitudinally of the-cover plates;-an actuating lever constituting means connecting the movable handle to thefixed handle for-swinging movement, said actuating lever 'being'pivotally connected at opposite ends to'the respective handles and being arranged to swing the movable handle longitudinally of the'fixed handle toward the jaws on exertion of pressure tending to'urge the handles toward one another; directionreversing means including a main lever rockable on the pivot pin and having pivotal connections at opposite ends thereof to the movable handle and center plate respectively, 'for imparting straight-line movement to the center-plate longitudinally of the fixed handle in'a direction opposite that given the movable handle; and toggle links articulated to the center plate and jaws respectively and effective to engage the jaw faces with a piece of work responsive to said movement of the movable handle toward the jaws and said movement of the center plate in an opposite direction.

8. A plier-wrench comprising a fixed handle including a pair of rigidly connected, spaced cover plates; a pivot pin and a guide lug secured to and extending transversely between the cover plates and spaced longitudinally of said handle; a movable handle disposed longitudinall-y'of the "fixed handle, said movable handle being connected to the fixed handle for swinging movement through. a path extending longitudinally of the fixed handle; a pair of elongated jaws extended longitudinally of the fixed handle and having innerend portions extending between the .cover plates, said jaws having parallel, workengaging jaw "faces at their outer ends; control links spaced longitudinally of the cover plates and of the respective jaws, said links being pivotally connected'atone end to the coverplates and at their other ends to said jaws to swing the jaws-toward one another while preserving the parallel relationship of the jaw faces ,in :selected positions ,to which the jaws areswung; :acenter plate enclosed by the cover platesv and disposed between the jaws, the center plate having a pair of spaced longitudinal slots receiving the pin and lug respectively, for straight-line "movement of the center plate longitudinally of the cover plates; anactuatinglever constituting means connecting the .movable handle to the fixed handle for swinging movement, said actuatinglever being pivotally connectedat opposite ends to the respective handles and being arranged to swing the movable handle longitudinally of the fixed handle toward the jaws on exertion of pressure tending to urge the handles toward one another; direction-reversing means including a main lever rockable on the pivot pinand :having pivotal connections at opposite ends thereof to themovable handle and center plate respectively, for imparting straight-line :movement to the-center plate longitudinally of the fixed handle in a direction opposite thatgiven the movable handle; and a pair of toggle links extending from each side of the center plate, the toggle links of each pair being pivotally connected at one end to the center plateandat their other ends to the jaw contiguous thereto at locations spaced longitudinally of the center plate and jaws, for shifting-the jaw faces into engagement with a piece of work responsive to said movement .of the movable handle toward the jaws and said movement-of the center plate in an opposite direction.

9. In a lock mechanism for a-plier-wrench, the combination, with a pair of transversely spaced handles, of a 'lever pivotally connected at opposite endsto the respective handles and including a latch .hook intermediate its ends; a trigger pivoted on one of the handles; a spring operatively-associated with the triggerand effective to bias the trigger to a'normalhandle-unlocking position, said trigger being manually shiftable against the action of the spring to a handle-locking position thereof; a rod'carri'ed by the trigger and arranged to beshifted longitudinallyof the handle on whichthe trigger is mounted .in one direction responsive to movement of the trigger to said handle-locking position; means on the rod engageable with the hook responsive-tomovement of the rod in said direction; and spring means operatively associated with said rod to urge the rod in an opposite direction, responsive to pressure exerted manually on the handles tending to urge them toward one another to an extent effective to disengage the hook from said means,

10. In a lock mechanism for a plier-wrench, the combination, with a pair of transversely spaced handles, of a lever pivotally connected at opposite ends to the respective handles and including a latch hook intermediate its ends, said hook being arranged for recessing thereof within one of the handles onshifting of the handles toward one another; a trigger pivoted on the handle within which the hook is recessed; a Spring operatively associated with the trigger and effective to bias the trigger to a normal, handle-unlocking position, said trigger being manually shiftable against the action of the spring to a handle-locking position thereof; a rod carried by the trigger and arranged to be shifted on one direction longitudinally of said handle responsive to movement of the trigger to its handle-locking position; a head on the rod engageable with the hook responsive to movement of the rod in said direction, to lock the handles to one another; and spring means operatively associated with said rod. to urge the rod in an opposite direction, responsive to further pressure exerted manually on the handles tending to urge them toward one another to an extent effective to recess the hook further within said handle and thereby disengage the hook from the head.

11. In a lock mechanism for a plier-wrench, the combination, with a pair of transversely spaced handles, of a lever pivotally connected at opposite ends to the respective handles and including a latch hook intermediate its ends, said hook being arranged for recessing thereof within one of the handles on shifting of the handles toward one another; a trigger pivoted on the handle Within which the hook is recessed; a spring operatively associated with the trigger and effective to bias the trigger to a normal, handle-unlocking position, said trigger being manually shiftable against the action of the spring to a handle looking position thereof; a block pivoted upon the trigger in spaced relation to the pivot axis of the trigger, so as to swing about said axis on pivotal movement of the trigger; a rod slidable in the block and arranged longitudinally of said handle; a head on the rod engageable with the hook responsive to movement of the rod in one direction, to lock the handles to one another; and a spring on the rod abutting at opposite ends against the head and block respectively and adapted to bias the head into engagement with the hook on swinging of the trigger to handle-locking position, further pressure on said handle being adapted to shift the hook out of engagement with said head, so as to return the trigger, rod, and head to handle-unlocking position under the action of the first named spring.

JOHN JOHNSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,568,934 Tull et a1. Jan. 5, 1926 2,206,251 Fischer July 2, 1940 2,320,303 Ross May 25, 1943 2,391,604 Wallace Dec. 25, 1945 2,443,153 Wells June 8, 1948 2,481,435 Mevnier Sept. 6, 1949 2,519,630 Boyer Aug. 22, 1950 2,553,400 Blair May 15, 1951 2,587,673 Aden Mar. 4, 1952 2,627,774 Walter Feb. 10, 1953 

